Human GLP-1 and analogues thereof have a low oral bioavailability. Exposure and bioavailability of human GLP-1 and analogues thereof is very low following oral administration. Human GLP-1 and analogues thereof can only be detected in plasma after oral administration if formulated with certain absorption enhancers in a specific amount. Steinert et al. (Am J Clin Nutr, October 2010; 92: 810-817) discloses oral administration of a tablet comprising GLP-1(7-36)amide and 150 mg sodium N-(8-(2-hydroxybenzoyl)amino)caprylate (SNAC). WO 2010/020978 dicloses an oral pharmaceutical composition comprising a protein and N-(8-[2-hydroxybenzoyl)amino)caprylate (SNAC).
There is still a need for an optimized pharmaceutical composition for oral administration of a GLP-1 agonist such as a GLP-1 agonist comprising a substituent.